What are Soft Tissue Sarcomas

Soft Tissue Sarcomas are a rare type of cancer that can develop from soft tissues like fat, muscle, connective tissue, nerve, blood and lymphatic vessels, joints, etc. In general, are listed as STSs a wide variety of tumors with heterogeneous histological characteristics, clinical features and different prognosis.

STS are rare tumors, they represent less than 1% of adult’s malignant tumors and 7.4% of pediatric malignant tumors. Most of them develop in the arms or legs (50-60%), less frequently they can arise in the retroperitoneum and abdominal cavity (15-25%), in the trunk (15-20%), and in the head-neck area (5-10%) (Table 1).

The incidence of STS is associated with exposure to chemical agents, ionizing radiations, virus as HSV8, immunodeficiency and hereditary diseases as type I and II neurofibromatosis, Li-Fraumeni Syndrome, Retinoblastoma, Familial Adenomatous Polyposis, and Werner Syndrome.

Classification of STS is based upon morphologic features and differentiation of the tumor cells.

The histological grade of STS (low, intermediate, high) is based on the presence of certain cellular characteristics associated with malignant biological behavior. For STS the histotype can predict the biological behavior (e.g. the Hemangiosarcoma is always high grade, the Dermatofibrosarcoma Protuberans is always a low grade disease).

STS usually have an infiltrating growth pattern. Tumor recurrence can be local or metastatic. Local recurrence is closely linked to the local treatment, which makes extremely important the adequacy of surgical margins. On the other hand, the metastatic spread (lung, liver, bone) is linked to the histotype and tumor grade. Lymphatic spread occurs rarely (5% of cases) and is most frequent in some type of STS such as Rhabdomyosarcoma, Malignant Fibrous Histiocytoma, Hemangiosarcoma, Clear-cell Sarcoma, Synovial Sarcoma, Epithelioid Sarcoma).

Considering the molecular biology STS can be divided into two groups: STS with chromosomal rearrangements (translocations) detected with conventional cytogenetic techniques; STS with molecular mutations (deletions, point mutations) not detected with conventional cytogenetic techniques.

STS can be initially asymptomatic and for that casually diagnosed or they can cause symptoms linked to the presence of the tumor compriming tissues and organs around (abdominal pain, early satiety, abdominal tension, intestinal sub-occlusion, fatigue, presence of a mass detectable with clinical examination).

The main instrumental tests are: Computed Tomography (CT), Nuclear Magnetic Resonance Imaging (NMRI), Positron Emission Tomography (PET) for the evaluation of tumor extension, and Image-guided Biopsy, in order to define the histological type and grade and then the successive treatment program.

Incidence< 1% of adult patients malignancies
7.4% of pediatric malignancies
SexM = F
Age< 40 years old: 21%
40-60 years old: 28%
> 60 anni: 52%
Location Arms and legs: 50-60%
Retroperitoneum and abdominal cavity: 15-25%
Trunk: 15-20%
Head and Neck: 5-10%
Incidence< 1% of adult patients malignancies
7.4% of pediatric malignancies
SexM = F
Age< 40 years old: 21%
40-60 years old: 28%
> 60 anni: 52%
Location Arms and legs: 50-60%
Retroperitoneum and abdominal cavity: 15-25%
Trunk: 15-20%
Head and Neck: 5-10%